GI Tract & Vessels (Ach) - W2 Flashcards
What is the function and features of the stomach?
- receives food + saliva from esophagus and acts as reservoir where the digestive enzymes can break it down.
- Parts
- greater curvature - attaches greater omentum
- lesser curvature - lesser omentum
- fundus - left 5th interspace
- cardiac orifice - has cardiac sphincter
- body
- pylorus
- rugae - folds
What are the parts of the pylorus of the stomach, and what does the pyloric sphincter do?
- Pyloric antrum
- pyloric canal
- pyloric sphincter
- controls passage of chyme into duodenum
- true sphincter - thick ring of circular muscle
- normally in tonic contraction
What are rugae, where are they found and what is their purpose?
- folds of mucosa inside stomach
- increase surface area
Most common of the hiatal hernias, how is it acquired, what is it a risk factor for and who is the most common population?
-
Acquired hiatal hernias
- most common (99%)
- occur in middle-aged people
- gastroesophageal region –> slides superiorly into thorax through lax esophageal hiatus
- risk factor for GERD
- What is the least common acquired hiatal hernia?
- what does it involve?
- When do you repair?
- what is it a risk for?
-
Paraesophageal (rolling) hiatal hernia
- less common (1%)
- pouch of perineum that contains the fundus of the stomach and extends for the esophageal hiatus ANTERIOR to the esophagus
- associated with pain, nausea, and vomitting
- refer for REPAIR
- high incidence of incarceration & ischemia
Peptic Ulcer
- what is it
- common site
- what can it cause
- erosion of the mucous membranes of the stomach or duodenum
- ONLY occurs in tissues in contact with gastric juices
- most common in duodenal cap (80%)
- 2nd most common is posterior wall of duodenum.
- erosion could perforate the wall & erode pancrease
- gastroduodenal artery massive hemorrhage
- associated w/H. pylori
How can you tell the difference between jejunum & ileum?
-
Jejunum
- often EMPTY
- thicker, redder, more vascular
- well developed circular folds of mucosa (plicae circularis)
- few arcade arterioles - much longer arterioles
- areas fat free
-
Ileum
- lymphatic nodules (peyer’s patches)
- more fat
- numerous, shorter arcade arterials
What are 3 things found on the large intestine and what are they?
- Teniae coli - outer longitudinal muscle fibers that are confined to 3 parallel bands
- Haustra - sacculations between teniae
- Appendices epiploicae - small sacs of fat covered w/peritoneum suspeneded from the external surface
What does inflammation of the appendix cause?
Where is pain referred intially and why?
What will become affected late?
-
Appendicitis
- when it ruptures can lead to peritonitis
- referred pain to T10 due to autonomic nerves and where they convege
- late = rebound tenderness at McBurney’s point - inflammation affects SNS of parietal layer
What is ulcerative colitis and what may be needed?
- severe inflammation and ulceration of the colon and rectum
- may need colectomy = permanet opening between ileum and anterior abdominal wall
What is a colostomie?
- establishes an opening between various parts of the colon and anterior abdominal wall - creates an artificial anus
What is a diverticululum?
What causes it?
Who is it common in?
Most commonly found where?
-
Diverticululum
- abnormal pouch that forms in the wall of the colon caused by increased intracolonic pressure pushing against weak intestinal wall.
- most commonly in sigmoid colon
- 10% of people over 40
- usually asymptomatic until inflamed
What are the 3 main arteries off the abdominal aorta?
- Celiac Trunk
- Superior mesenteric artery
- Inferior Mesenteric artery
What does the celiac trunk supply?
where does it arise?
What are its branches?
- supplies foregut
- arises from abdominal aorta T12
- Branches
- left gastric
- Common hepatic
- Splenic
What are the two branches of the common hepatic?
- Hepatic artery proper
- Gastroduodenal artery
What are the branches of the hepatic artery proper?
- Right gastric - lesser curvature
- Left hepatic - left lobe of the liver
- Right hepatic - right lobe of liver
- Cystic artery - usually arises from right hepatic to supply the gallbladder
What are the branches of the splenic artery?
Where does splenic lie and what is its course?
- looks TORTUOUS - lies above pancreas
- Branches
- Pancreatic branches
- Short gastric (fundus)
- Left gastro-omental (gastro-epiploic)
What are the branches of the gastroduodenal artery?
- supraduodenal
- superior pancreaticoduodenal arteries
- right gastro-omental (gastro-epiploic)
Superior Mesenteric Artery
- What does it supply?
- Where does it arise?
- Where do its branches go and what do they supply?
- midgut
- arises from abdominal aorta 1cm below celiac trunk at L1
-
Small intestine
- inferior pancreaticodudoenal arteries
- jejunal
- ileal
-
large bowel
- ileocolic - has appendicular branch
- right colic
- middle colic- transverse mesocolon
Inferior Mesenteric Artery
Supplies?
Arises?
Branches?
- hindgut
- arises 1.5 inch above abdominal aorta bifurcation at L3
- Branches - gut to lower rectum
- Left colic artery
- Sigmoid arteries
-
Superior rectal artery (termination of inferior mesenteric)
- Marginal artery
What artery do the SUPERIOR mesenteric and INFERIOR mesenteric arteries form an anastomes between?
left colic artery anastamoses with middle colic (of superior mesentery)
What artery at the ileocolic junction forms an anastamoes with the superior rectal artery - forms an anatomoes between COLIC ARTERIES
marginal artery of Drummond
What are the 2 sets of capillaries though which the portal system flows?
- GI capillaries
- Liver capillary beds
What vein drains the foregut?
splenic vein
How is the hepatic portal vein formed?
- splenic vein recives gastric, gastroepiploic and pancreatic veins
- receives inferior mesenteric vein
- joins with superior mesenteric vein for form the hepatic portal vein
forms posterior to the neck of the pancreas
What anastomoses is important for forming esophageal varices?
- esophageal tributes of azygos and hemiazyogus veins w/tributaries of left gastric vein
What anastomoses is responsible for forming caput medusae (engorgement of epigastric veins)
- Paraumbilical veins w/superior, inferior, and superficial branches of epigastric veins
What anastamoses is responsible for forming internal hemorrhoids
- superior rectal vein (portal)
- middle rectal vein
- inferior rectal vein
What is the cause of portal hypertension?
- increase in pressure and engorgement of vessels from obstruction of portal circulation
- within liver, tumor/cirrhosis
- outside liver - compression of portal vein (tumor)
What are the symptoms of portal hypertension?
- ascites
- GI bleeding - esophageal varices, rectal hemorrhoids
- splenogmegaly
- caput medusae
What receives lymph from the abdomen
cisterna chyli
Where does lymph flow from the jejunum, ileum and colon?
aorta
What are the 3 nodes that lie adjacent to each of the unpaired arteries
celiac node
superior mesenteric node
inferior mesenteric node
What organs does the celiac trunk supply (6)
- stomach
- duodenum
- liver
- gall bladder
- pancrease
- spleen
If the gastric ulcer erodes the stomach wall, what artery could cause a GI bleed?
splenic artery
What organs does superior mesenteric artery supply?
- Pancreas
- duodenum
- jejunum
- ileum
- cecum, appendix
- ascending colon
- hepatic flexure
- proximal 1/3 of transverse colon
What does the inferior mesenteric vessels supply?
- distal 2/3 of transverse colon
- descending colon
- sigmoid colon
- rectum
What areas of the colon are prone to ischemia?
- right colon - marginal artery is poorly developed
- splenic flexure
- rectosigmoid junction - distal to last collateral connectiion
What vein enters the liver and what vein leaves the liver?
Hepatic portal vein enters
hepatic vein leaves
